1. Field of the Invention
The present invention relates to a synchronous type serial communication circuit for carrying out no contact point communication by an electromagnetic induction system and employing a portable information apparatus.
2. Description of the Prior Art
For the data transfer by use of the electromagnetic induction system in conventional portable information apparatuses, there is non synchronizing communication by use of a start-stop synchronizing system, or synchronizing communication for separately transferring the clock and data by providing a plural number of coils. In the case of communication by the start-stop synchronizing system a control clock of at least 8 or 16 times the transfer speed becomes necessary so that the system becomes difficult to be realized. In the case of the synchronizing communication utilizing a plural number of coils, a plural number of coils becomes necessary, and it is necessary to make the winding direction of the coils in the same direction.